Gravity fill systems for filling potable water storage tanks used in aircraft and the like are generally known. However, a need exists for better venting of air from inside the tank to ambient during filling. Insufficient venting unnecessarily prolongs the time needed to fill the tank with water.
An option is to add valves, lines and controls to better vent the tank during filling. However, this greatly adds to the cost and complexity of the system and requires the operator to open and close valves during servicing of the tank.